#include <stdio.h>
#include<iostream>
#include<math.h>
using namespace std;
class Ellipse
{
	int x1, y1, x2, y2;
public:
	void Getx1(int X1, int Y1, int X2, int Y2)
	{
		x1 = X1;
		y1 = Y1;
		x2 = X2;
		y2 = Y2;
		cout << x1 <<' ' << y1 <<' ' << x2 <<' ' << y2 << endl;
	}
	double Area()
	{
		return abs(x1) * abs(y1) * 3.1415;
	}
};
int main()
{
	int X1, Y1, X2, Y2;
	cin >> X1 >> Y1 >> X2 >> Y2;
	class Ellipse e;
	e.Getx1(X1, Y1, X2, Y2);
	double f = e.Area();
	cout << f;
	return 0;
}